Articular cartilage is a smooth, resilient tissue which covers the opposing ends of bones and facilitates the smooth movement of the bones relative to one another. However, when articular cartilage is damaged (e.g., through injury or prolonged wear), subsequent motion of the bones tends to increase that damage, ultimately causing the cartilage to wear away completely. When this occurs, the bones rub directly against one another, typically resulting in substantial pain for the patient and reduced mobility of the joint. In many cases, such damage to articular cartilage can lead to osteoarthritis.
Microfracture therapy is an orthopedic procedure which can help to restore articular cartilage. More particularly, microfracture therapy creates tiny fractures in the cortical bone bed disposed immediately below the damaged articular cartilage. In cases where the native cartilage has been damaged beyond repair or has been surgically removed, microfracture therapy can be applied to the exposed cortical bone bed. These micro fractures permit blood to seep out of the underlying cancellous bone to the surface of the cortical bone bed and essentially create blood clots which release cartilage-building cells. These cartilage-building cells then result in the formation of replacement hyaline-like cartilage, fibrous tissue and/or fibrocartilage.
In addition to the foregoing, microfracture therapy can also be used to enhance the attachment (or re-attachment) of soft tissue to bone, e.g., to attach (or re-attach) a ligament to bone or to attach (or re-attach) a labrum, labral/chondral junction (i.e., the “transition zone” between cartilage and the labrum) or cartilage to bone. In this situation, the microfracture therapy creates tiny fractures in the cortical bone bed disposed immediately below the location where the soft tissue is to be attached to (or re-attached to) the bone, thereby permitting blood to seep out of the underlying cancellous bone, essentially creating blood clots between the soft tissue and the bone which release restorative cells at the surgical site.
To date, microfracture therapy is generally performed using a small, sharp pick or awl to create the small microfracture holes in the cortical bone bed. However, such picks or awls are generally used by driving them longitudinally, e.g., with a hammer or mallet, thereby requiring substantially direct linear access to the bone surface which is to receive the microfracture therapy. Furthermore, where the microfracture must be created in a bone surface which is not substantially aligned with the angle of access, it can be difficult to generate the forces required for the pick or awl to penetrate the hard cortical bone and release blood from the underlying cancellous bone.
In many cases, e.g., for certain sites on the lower femur, such direct linear access to the microfracture site may be readily available. However, in other cases, intervening anatomical structures can make it difficult or impossible to obtain direct linear access to the microfracture site, and hence can make it difficult or impossible to use a conventional pick or awl to provide microfracture therapy to the bone. This is particularly true where the microfracture surgery is to be performed arthroscopically. By way of example but not limitation, it can be difficult or impossible to arthroscopically provide microfracture therapy to the acetabular cup of the hip using a conventional pick or awl, given the anatomical constraints typically imposed in arthroscopic hip surgery.
The present invention is intended to provide a novel method and apparatus for providing arthroscopic microfracture therapy, particularly in locations where it is difficult or impossible to utilize a conventional pick or awl in the microfracture therapy.
The present invention is also intended to provide a novel method and apparatus for securing soft tissue to bone.